Analog Devices has announced the availability of a new PLL (phase locked loop) synthesizer for applications in microwave point-to-point systems, PMR (private mobile radio), VSATs (very small aperture terminals), test and instrumentation equipment, and aerospace systems. The ADF4150HV 4.4 GHz fractional-N or integer-N PLL synthesizer features a 30-V charge pump. The device can be used to directly drive high tuning-voltage external VCOs (voltage controlled oscillators), therefore it eliminates the need for active loop filters.
The ADF4150HV is designed based on RF and PLL synthesizer design. It exhibits improved synthesizer phase noise performance by allowing the use of passive loop filter topologies. The frequency divider allows the VCO frequency to be divided by 2, 4, 8 or 16 thus allowing generation of output frequencies as low as 31.25 MHz. This system is used in systems that require high performance and wide tuning angle. It is supported by ADIsimPLL Version 3.3 design tool
Other features include:
--High voltage charge pump: 6 to 30 V
--3 to 3.6 V power supply
--Programmable dual-modulus prescaler of 4/5 or 8/9
--Programmable output power level and charge pump currents
--Analog and digital lock detect
--Slew mode for fast lock
Price: Each US$2.49 for 10,000-unit quantities
Analog Devices has also introduced phase-locked loop (PLL) circuit design and evaluation tool ADIsimPLL Version 3.3 for evaluating, designing, and troubleshooting RF systems using Analog Devices' family of PLL synthesizers. This software tool can be freely downloaded from www.analog.com/ADIsimPLL.
ADIsimPLL Version 3.3 is compatible with previous versions of the software tool and has been enhanced by adding support for 16 new devices, increased phase noise modeling accuracy and Fractional-N spur level estimation, New Design Wizard, Time Simulation Engine and Time Domain Simulator features. Some of the new devices included in this version is ADF4150HV and ADF4158 synthesizers, ADF5000, ADF5001 and ADF5002 RF prescalers, highly integrated ADRF670x quadrature modulators with integrated Fractional-N PLL, ADRF660x mixers with integrated Fractional-N PLL and VCO, ADRF6750 quadrature modulator and ADRF6655 mixer. It also has the ability to derive additional frequency outputs by dividing the VCO signal. There have also been significant improvements and enhancements to the tool's simulation and evaluation capabilities. The phase noise simulation algorithms have been improved by the addition of the 1/f phase noise contribution from the digital dividers and the phase detector, resulting in highly accurate phase noise predictions from close to the carrier all the way to the broadband noise floor.
To assist in estimating the level of Fractional-N spurs, a new estimate of the worst case magnitude of the first three Fractional-N spurs is now calculated and displayed on the phase noise plots, which allows the user to evaluate different loop filter topologies and design parameters in order to manage the effect of these spurious signals. The design tool has enhanced the time domain simulator to model various modulation options and the New Design Wizard so that the user can select from the range of options to generate the desired frequency. An output page for the secondary output is also provided allowing different configuration options to be selected when the phase noise is displayed, and the Time Simulation Engine has been enhanced to accurately model the effect of the anti-backlash pulse.
To know more visit: www.analog.com